Brake mechanism.



W. P. COLLINS.

. BRAKE MECHANISM.

APPLICATION FILED MAR. s, 1913.

Patented Feb. 10, 1914.

J? ,0 6/71/60 7? Way/M UNITED STATES PATENT OFFICE.

WILLIAM P.'COLLINS, OF BOSTON, MASSACHUSETTS, ASSIGNOR TO AUTOMATIC AIR BRAKE COMPANY, OF BOSTON, MASSACHUSETTS, A CORPORATION OF MASSACHU- SETTS.

BRAKE MECHANISM.

To all whom it may concern:

Be it known that I, VILLIAM P. CoLL Ns, a citizen of the United States, residing at Boston, in the county of Suflolk and State of Massachusetts, have invented new and useful Improvements in Brake Mechanisms, of which the following is a specification.

This invention relates to new and useful improvements in brake mechanisms, particularly of the rotary fluid type.

The aim of the invention is to provide a device comprising a stationary member and arelatively rotary member, one of which is provided with a plurality of chambers disposed diametrically opposite each other about the periphery of the other member, while said other member comprises a plurality of pistons normally adapted to alternately draw fluid into said chambers and to eject said fluid therefrom with practically no resistance to the movements of said fluid. Through this arrangement of the various parts, the casing, which comprises the several chambers, will be evenly balanced, consequently permitting either of said members to be rotated relatively to the other without causing unnecessary vibration.

The object of the invention is further to provide valves for each of said chambers which may be opened and closed to uniformly and gradually retard the passage of said fluid from and to said chambers and thus prevent any sudden stops and consequent injury to the moving parts of said device.

The invention consists in the combination and arrangement of parts whereby the above objects and certain other objects hereinafter appearing may be attained, as set forth in the following specification and particularly pointed out in the claims.

Referring to the drawings: Figure 1 is a sectional elevation through a brake mechanism embodying my invention. Fig. 2 is a side elevation, partly in section, of the same. Fig. 3 is a detail sect-ion taken on line 33 of Fig. 1.

Like numerals refer to like parts throughout the several views of the drawings.

In the drawings, 5 is a casing within which a piston carrier 6 is arranged. In width said casing is preferably equal, upon the interior thereof, to the diameter of the piston carrier 6. Said casing is however elongated at points diametrically opposite each other Specification of Letters Patent.

Application filed March 3, 1913.

Patented Feb. 10,1914.

Serial No. 751,936.

to provide chambers 7 and 8 which are preferably crescent shaped, the wall 9 of the chamber 7 being eccentrically disposed relatively to the median axial line of the carrier 6, while the wall 10 of the chamber 8 is also eccentrically arranged relatively to the median axial line of said carrier 6, but with the center of said eccentric portion lying upon the opposite side of said median axial line diametrically opposite that of the center of the wall 9, thus making said casing symmetrical relatively to the axis of said carrier 6, consequently should it be desired to rotate said casing there would be practically no vibration created thereby. In some of the many uses to which the device, herein shown, is adapted it might be preferable to rotate said casing and as, hereinbefore stated. In the present adaptation of the device however it is preferable that the piston carrier 6 be the rotatable member.

The carrier 6 is provided with a series of radially disposed slots 11 within which are arranged piston blades 12 provided at their outer ends with rods 13 arranged in slots 14: extending longitudinally of said blades, said rods being adapted to engage the inner wall of the casing 5 which includes both of the chambers 7 and 8. Springs 15 normally retain said rods in yielding contact with said walls during the revolutions of said blades consequent to the rotation of said carrier 6 and thus to prevent the escapement of the fluid which is contained within said chambers 7 and 8 during the movements of said pistons therethrough. The pistons 12 are further provided with rollers 16 at their inner ends which are adapted to engage means, preferably flanges 17 formed upon the end walls 18 of the casing 5, said end Walls being separably secured to the body of said casing by bolts 19. The flanges 17 are of like conformation to the inner wall of said casing 5, consequently as said pistons are revolved about the median axial line of the carrier 6 a constant pressure will be maintained thereby against said wall. Said flanges 17 are furthermore preferably formed integral with the walls 18 and extend inwardly into recesses 20 formed for that purpose in the carrier 6. The carrier 6 is secured to a driving shaft 21 journaled to rotate in bearings 22, 22 in the end walls 18, 18 of said casing. The casing 5 is furthermore provided with ports 23 and 24 at k opposite ends respectively of each of the chambers 7 and 8. During the normal operation of the device these ports will remain open and consequently as said pistons 12 revolve through the chambers 7 and 8, fluid will be drawn into said chambers through the ports assuming that said carrier is rotating in the direction of the arrow a, and while said pistons are moving from points abreast said ports to the points b Fig. 1, by reason of the fact that said chambers between the points mentioned aregradually increasing in cross sectional area and consequently forming a partial vacuum each time a piston passes said ports on its way to the point 1). From the point Z) to the port 2 1 the fluid which has been drawn into said chamber by one of said pistons will be ejected through said port 24 by the next succeeding piston, each piston acting to draw fluid into said chamber and to eject the fluid drawn into the same by its. preceding piston, this action of said pistons being identical in both of the chambers 7 and 8. The ports 23 and 24 are preferably of sufficient size to permit the fluid agitated by said piston to have a free passage therethrough to prevent resistance during the normal operation of the device. When however it is desired to check the relative rotary movements between said carrier and said casing these ports are provided with valves by which they may be gradually closed, whereby the drawing in and ejecting of said fluid may be retarded so gently that no unnecessary shock or jar will be imparted to the rotating parts of said device and the mechanism connected to said rotating member.

In the successful accomplishment of the above, closing valves 25 are provided, one of the same being illustrated in Fig. 8, which for the sake of clearness has been referred to as a section taken on the line 3-3 of Fig. 1. This preferably comprises a stem or casing 26 having a passage 27 extending therethrough communicating with the chamher 7 and closed at its outer end preferably by a cap 28 secured thereto by screws 29 and constituting a bearing for a rotary member 30, which is arranged within said passage 27 and is provided with a passage 31 extending therethrough longitudinally rela tively to the passage 27. The cap 28 is also provided with a passage 32. The lever 33 is secured to the rotary member 30 of each of the valves 25 while all of said levers are preferably connected with a rectangular frame 34 whereby all of saidlevers 33 may be rocked simultaneously to rotate their respective rotatable members 30 to aline or disaline the passages 31 and 32 and said ports will be opened and closed. The rotary member 30 is also provided with means to force the same against said cap during the closing movement of said valve, said means preferably comprising a series of sharp pitch screw-threads 35 which are engaged by correspondingly arranged screwthreads 36 formed upon the rotary member 30, only a partial rotation of said member being required to cause the outer face 3'1 of said member 30 to engage the inner face 38 of the cap 28 to securely close said valve.

Having thus described my invention, what I claim and desire by Letters Patent to secure is:

1. A brake mechanism having, in combination, a piston carrier, a casing within which said carrier is arranged means adapted to rotate one of the aforesaid members relatively to the other, said casing having a chamber formed therein outside of and adjacent to the periphery of said carrier, a series of pistons carried by said carrier, means to move said pistons to engage the inner wall of said casing within said chamber during the relative movement of said carrier and said casing, valves located at opposite ends of said chamber, said valves comprising a hollow stem, a cap plate for said stem, said cap having an opening extending therethrough, a rotatable member mounted in said cap having a passage extending therethrough substantially parallel with the axis of said rotatable member adapted to aline with the opening in said cap, and means to rotate said rotatable member to aline and disaline said passage and said opening whereby said valve will be opened and closed respectively.

2. A brake mechanism embodying in its construction a casing comprising a fluid chamber, pistons adapted to be moved through said chamber to alternately draw fluid into and eject fluid from said chamber, valves adapted to check the drawing in and ejection of said fluids relatively to said chamber whereby the movements of said pistons will be retarded, said valves comprising a hollow stem, a cap adapted to close said stem and having an opening extendin therethrough, a rotatable member mounte in said cap having a passage therethrough adapted to aline with the opening in said cap, means to rotate said rotatable member to aline and disaline said passage and said opening, and means to move said rotatable member toward and away'from said cap.

3. A brake mechanism embodying in its construction. a casing comprising a fluid chamber, pistons adapted to be moved through said chamber to alternately draw fluid into. and eject fluid from said chamber, said chamber having ports disposed at opposite ends thereof adapted to permit a free passage of said fluid therethrough, valves adapted to regulate the passage of fluid through said ports, each of said valves comprising a casing, a cap adapted to close the end of said casing having an opening exber may be moved toward or away from tending therethrough, a rotatable member said cap to open and close said valve.

mounted in said cap, said rotatable member In testimony whereof I have hereunto set having a passage extending longitudinally my hand in presence of two subscribing Wit- 5 therethrongh, means to rotate said rotatable nesses.

member to aline and disaline said passage and said opening, and screw-threads formed upon the interior of said casing adapted to Witnesses:

be engaged by screw-heads on said rota- SYDNEY E. TAFT, 10 table member whereby said rotatable meml ANNIE J. DAILEY.

WVILLIAM P. COLLINS.

Copiesof this patent may he obtained for five cents each, by addressing the Commissioner 0! Iatents. Washington, D. C. 

